通过波导结构设计以及色散调控,基于孤子脉冲压缩、自相位调制和光波分裂效应,用0.22 m反常色散五氧化二钽波导级联0.9 m正常色散五氧化二钽波导产生在1 520~1 580 nm波段具有4 dB平坦度、60 nm带宽的平坦光频率梳.利用X-Frog技术分析了脉冲在传输过程中的时谱演化,并且研究了产生光频率梳的相干性.时谱演化指出自相位调制和光波分裂的共同作用使得光频率梳的光谱包络变宽,并且具有良好的平坦度.一阶复互相干度计算指出光频率梳具有较好的相干性.仿真结果表明, 五氧化二钽集成非线性光波导在产生高重复频率平坦相干宽带光频率梳方面具有较好的前景.

Through the waveguide structure design and dispersion engineering, based on the soliton pulse compression, self-phase modulation, and optical wave breaking, a 0.22 m anomalous dispersion tantalum pentoxide waveguide cascaded with a 0.9 m normal dispersion tantalum pentoxide waveguide was used to produce a flat optical frequency comb with a 4 dB flatness and 60 nm bandwidth in the 1 520 nm to 1 580 nm. The spectrogram evolution during the pulse transmission process was analyzed through the X-Frog technique, and the coherence of the optical frequency comb were also studied. The analysis indicates that the self-phase modulation and optical wave breaking effects make the comb spectrum envelop broadened and flattened. The first-order mutual coherence function calculation indicates that the optical frequency comb has good spectral coherence. The simulation results show that the tantalum pentoxide integrated nonlinear optical waveguide has a good prospect in the generation of high repetition rate flat coherent broadband optical frequency comb.